The present invention relates to electromagnetic read/write, information storage and retrieval systems, and in particular, to the structural merging in such systems of electrical and mechanical functionality, and to ancillary matters that surface as structural, organizational opportunities as a result of such merging. Recognizing that the various features of the invention can have important applicability in a wide range of kinds of such systems (e.g., rigid-disk, floppy-disk, drum, tape, etc. systems), the description which follows herein focuses attention on rigid-disk systemsxe2x80x94an arena which is most central in today""s commercial applications. Accordingly, specification and claim references made herein to rigid disks should be read to include these other-kinds-of-media systems.
Given the merged-functionality aspect of the present invention, many features thereof, accordingly, focus upon improvements in mechanical load-bearing and in motion-articulating characteristics of transducers, and of flexures which carry such transducers, that are used in these kinds of systems. In this context, the field of the invention encompasses systems wherein (a) a read/write transducer flies over a media recording surface, (b) such a transducer is intended for contact-capable operation, and operates with intermittent media-surface contact, and (c) such a transducer is intended for contact-capable operation, and operates in substantially continuous contact with a media recording surface.
In the march of progress which has characterized ongoing development of disk-drive, electromagnetic read/write systems, the quests for enlargement of a real recording density, and for improved-quality read/write signal communication between a disk""s recording surface and a transducer, have been high on the list of technical interest and relentless pursuit. This situation has been reflected, inter alia, in significant reductions in components"" sizes and masses, by reductions in the xe2x80x9ceffective massesxe2x80x9d of those components which react dynamically during read/write operations, and in dramatic reduction in the separation which exists between the working read/write zone of a transducer and a disk""s recording surface. These advances include, according to an important line of development by the Censtor Corporation of San Jose, Cali., system embodiments in which a read/write transducer operates in substantially continuous sliding contact with such a recording surface. The latter line of advancement in the art of disk-drive recording is well illustrated and expressed in the parent patent and patent applications which have been set forth hereinabove.
Pausing for a moment at this point to focus upon prior art efforts by others to bring about size reductions, it is important to bear in mind that these prior art changes have, by and large, been accomplished with what might be thought of as a segregated rather than a merged focus upon the three core functionalitiesxe2x80x94electrical, mechanical and magneticxe2x80x94of read/write transducers and supporting flexures. In other words, prior art thinking has looked upon the respective components in this environment which offer each of the individual functionalities as being essentially independent of the other-functionality components. As a consequence, there has been somewhat of a naturally perceived limit in how far one can go to bring about significant size reductionxe2x80x94a limit dictated by functional performance constraints, and even more appreciably, probably, by manufacturing-costs and manufacturing-capabilities constraints.
Specifically, and looking for a moment just at the issue of mechanical load bearing, prior art thinking has been based upon the notion that once necessary mechanical load-bearing requirements are known, all of that structure which has been looked upon in the past as being the sole constituent attending to that functionality can only be reduced in size just so much if it is to remain practically manufacturable. However, beginning with the work of Hal Hamilton as such is expressed in the above-referred-to ""932 patent, a new kind of thinking has entered this art, whereby xe2x80x9cmerger of functionalityxe2x80x9d is viewed as providing an opportunity for retaining all necessary electrical, mechanical and magnetic capability, while at the same time allowing for substantial shrinking of overall size, and actual improvement in practical manufacturability. More particularly, in the Hamilton ""932 disclosure, there surfaces a recognition that electrical current-carrying structure can be utilized significantly to carry mechanical load, and conversely, that mechanical load-bearing structure can be utilized significantly to carry electrical current. In other words, what might be thought of as singular-character structure, or material, functions in multiple ways. Not only does this unique way of thinking about merged-functionality yield surprising size- and mass-reduction opportunities, but also it tends to lead toward structures which are inherently simpler in form and in construction, and less complex and costly to fabricate.
It is this xe2x80x9cmerged-functionalityxe2x80x9d view which underlies key contributions made to the art by the present invention.
Continuing, and directing attention to other matters upon which this invention is focussed, in the ever more intimate environment of the interface between a disk""s recording surface and a read/write transducer, and in addition to the size, mass, effective mass and spacing issues just generally expressed, many other considerations sit as important participants at the table of key technical concerns. For example, tight control over, and maintenance of, a very precise XYZ spacial location of a transducer in relation to a disk surface is critical, as is the ability of the transducer and supporting flexure structure to respond rapidly and fluidly to disk-surface topographical features, and/or to other things and events which require speedy, accommodating, operating-attitude adjustment. This kind of adjustment must take place in a manner minimizing as much as possible any occasions of signal-communication drop-out, and in a manner free of disruptive resonance vibrations. Attention also must be addressed to damping and shock-absorbing issues.
All of these considerations need to be taken into account as well (a) in systems where a transducer flies over a disk""s recording surface, (b) in systems where contact operation occurs (intermittently or continuously), and (c) in systems which, on the one hand, have gimbaled transducer structures, and on the other hand, non-gimbaled transducer structures.
In the gimbaled transducer setting, the merged functionality focus aspect of the invention opens the door to the fabrication and use of a load-bearing transducer chip which has a substantially planar body, with plural, projecting disk-surface contact feet, or pads, and which can operate, relative to a disk""s recording surface, with substantially a zero-angle-of-attack, and with the read/write portion of the transducer in intimate contact with that surface. This, in turn, offers the opportunity for electromagnetic design which occupies space in the plane of the body, and which allows for placement of the read/write zone anywhere relative to that body.
Given the above remarks and comments, it is an important object of the present invention to offer transducer/flexure improvements along the lines just suggested xe2x80x94focused on the notion of structural merging, for example, of electrical and mechanical functionality.
A related object of the invention is to provide such improvements which lead toward simple, low-cost, low-mass structures that offer the opportunity for appreciable enlargement in areal density of recorded information, with reliable and improved signal-communication characteristics.
Thus, an important object is to provide a head/flexure structure which includes load-bearing (merged-functionality) conductors.
A related object is to provide a head/flexure structure in which the conductors perform mechanical functions in addition to their function of conducting electrical signals between a head and other circuitry.
Still another object of the invention disclosed herein is to provide a flexure/conductor structure which supports a head in a precise location and orientation relative to the surface of a medium.
Yet a further invention object is for the head-supporting flexure to be capable of supporting the head in a contacting relationship with the disk while reading or writing, without the occurrence of catastrophic head crash events or excessive interface wear.
Also, an object of the invention is to provide a flexure/conductor structure which is capable of moving the head along a Z-axis, i.e., that axis which is normal to the surface of the disk, with a minimal degree of angular rotation, i.e., minimizing the angular constant.
Another object is to provide a flexure/conductor structure which exhibits maximum levels of lateral and torsional resonant frequencies with the minimal amount of gain.
Still a further object is to provide a transducer/flexure/conductor structure which has a minimal number of parts, and which can be produced by a relatively straight-forward and cost-effective process, including, in certain cases, an automated assembly process.
Another object is to provide a flexure/conductor structure which is capable of compensating for topographical irregularities in the surface of the recording medium.
Yet another object of the invention is to provide a flexure/conductor structure in which the head is allowed a certain range of pitch and roll movement independent from the flexure.
A further object is to provide a head/flexure structure which has a tunable hinge near its proximal end.
Other objects include providing a head/flexure structure which: (a) is wireless; (b) is amenable to compact disk-to-disk stacking; and (c) contains more than one pair of conductors.
Still a further object is to provide a head/flexure structure which has a gimbal including conductive articulators.
Thus, the inventive subject matter presented herein regards improvements in transducer/flexure structure for an electromagnetic read/write system, and relates, inter alia, to structures, such as flexures, for carrying electromagnetic read/write transducers, and more particularly, to such structures wherein electrical conductors which connect with such transducers are utilized significantly, in an augmentive way, as mechanical load-bearing and articulating elements in the structures. The subject matter of the invention also relates to contact-capable read/write systems in which the read/write transducer acts directly as a load-bearing structure under disk-contact conditions. According to an important aspect of the invention, therefore, such augmented-role conductors play the dual roles of (a) conducting electrical signals between a transducer and remote, external circuitry, such as a signal processor, and (b) at the same time supporting mechanical load (such as a bending and/or articulating load), including, in certain embodiments, 100% of that load in a certain portion or region of a transducer-carrying structure.
Fundamentally, the subject matter of the present invention rests on several key concepts, some of which spring from the notion that innovation in the load-carrying/articulation characteristics of transducer-carrying structure can significantly enhance overall read/write system performance. One of these conceptsxe2x80x94based upon a new and striking xe2x80x9cmerged-functionalityxe2x80x9d recognitionxe2x80x94is that the very same conductors which carry signal-bearing information to and from a read/write transducer can also function mechanically as the articulating and load-bearing beam structure which carries and supports such a transducer, statically and dynamically, for instance, in the setting of a cantilever-type support arrangement for a disk read/write transducer. This conceptual thought carries also into an arrangement where, effectively, the transducer is supported for gimbaling action, with the recognition that what might be thought of as the gimbal articulators (hinges or torsional beams) can be formed by electrical-current-carrying conductors.
Another foundation concept is that the flexure/beam transducer-carrying construction can take important advantage of what can be viewed as bilateral motion independence, wherein a pair of spaced beam components afford a single- or dual-axis articulation capability to a supported transducer. Indeed, such construction can enable dual-degree-of-motion gimbal action (as just suggested above) for such a transducer. The shift of mechanical articulation and load-bearing responsibilities to signal-carrying conductors is an especially useful concept in so-called micro-flexure designs where extremely small mechanical structures are involved.
A further important concept is that a read/write transducer can itself be utilized as a load-bearing structurexe2x80x94a concept leading, inter alia, toward minimizing of the size and mass of the overall transducer/flexure/conductor structure.
In addition to the structural contributions made by the present inventive subject matter, also furnished thereby are novel methods of producing micro-transducer-support structures employing signal-carrying conductors as mechanical load-bearing/articulating elements such, for example, as hinges, torsional beams, etc.
These and other objects, advantages and features that are offered by the present invention will become more fully apparent as the description which now follows is read in conjunction with the accompanying drawings.